This project is dedicated to finding out which endocrine factors participate in the genesis and development of cancer in hormone target tissues such as the breast, prostate, endometrium and adrenals. Specifically, efforts are directed to the detection of significant differences in the secretion and/or disposition of pituitary, adrenal and gonadal hormones in individuals with endocrine related cancers relative to matched normal controls. To learn whether endocrine disturbances precede the clinical diagnosis of the disease a similar search for endocrine profile differences between healthy subjects identified as at high risk for specific cancers and matched low risk controls is also part of this project. Because of the intricate interrelationship of the various hormones emphasis is given to obtaining the complete endocrine profile in each subject studied. Since the significance of the quantitatively minor metabolites is not known the program is also concerned with developing methodology for the detection and measurement of these substances and including them in the screening studies. The pulsatile secretory nature of many hormones renders single sample plasma determinations of questionable value and therefore the project focuses on obtaining highly accurate mean plasma values by frequent sampling over 24 hours. BIBLIOGRAPHIC REFERENCES: Fishman, J., Naftolin, F., Davies, I.J., Ryan, K.J., and Petro, Z. Catechol Estrogen Formation by the Human Fetal Brain and Pituitary J. Clin. Endo. and Metab. 42:177, 1976. Fishman, J. and Hellman, L. 7 Beta-17 alpha-Dimethyltestosterone (Calusterone)-Induced Changes in the Metabolism, production Rate, and Excretion of Estrogens in Women with Breast Cancer: A Possible Mechanism of Action. J. Clin. Endo. and Metab. 42:365, 1976.